{"id":"71fa6596-6a54-4d5f-ac21-dd62877d8016","arxiv_id":"2608.02342","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":4,"one_line_summary":"NbNiTe5 becomes superconducting under pressure at the same time it begins to amorphize, with Tc rising slowly to 1.4 K by 45.7 GPa.","lead":"Applying high pressure to the layered material NbNiTe5 makes it begin turning amorphous at about 10 GPa, and at almost the same pressure it starts to superconduct. The finding adds a rare case where structural disorder and superconductivity appear together, giving physicists a new platform to study how messiness affects superconductivity.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Superconductivity evidence is only a partial resistance drop with a 90%-onset criterion and no zero-resistance or shielding data; a filamentary or impurity origin would invalidate the central concurrent amorphization-SC claim.","rationale":"The reader's weakest assumption identifies exactly the load-bearing concern: the superconductivity claim is supported only by a partial resistance drop and magnetic-field suppression, with no zero-resistance or shielding data. This is the most critical point because both the title and abstract center on the concurrence of amorphization and superconductivity; if the SC is filamentary or from an impurity, the paper's main novelty and the disorder-Tc correlation are unsupported. Alternative concerns—such as the lack of a pressure medium in XRD causing possible non-hydrostatic amorphization, or the absence of a quantitative disorder metric—are real but secondary. The XRD and Raman amorphization evidence is internally consistent and more robust. A conditional verdict is appropriate: the observations are suggestive but need bulk SC confirmation. Our stress test does not change this assessment; the same single decisive check (AC susceptibility under pressure) would resolve the concern. Therefore, we agree with the reader and recommend no change to the verdict.","tokens_in":7582,"tokens_out":7626,"duration_ms":66848,"concrete_test":"Perform AC magnetic susceptibility measurements using a mutual-inductance coil integrated into a diamond anvil cell at 45.7 GPa (and near 10 GPa if possible). A diamagnetic shielding signal with a volume fraction >10% of the sample would confirm bulk superconductivity; a negligible or absent shielding signal (<2%) would support the filamentary- or impurity-phase interpretation and invalidate the central claim of bulk disorder-enhanced superconductivity.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim that superconductivity emerges concurrently with amorphization and is modulated by disorder rests entirely on a partial resistance drop observed in transport under pressure (Figure 2d-f). The authors define Tc as the temperature where resistance falls to 90% of its normal-state value, but do not report a zero-resistance state, Meissner effect, or specific-heat anomaly. The drop is suppressed by magnetic field at 31.0 and 45.7 GPa, which is consistent with superconductivity, but does not establish whether it is bulk, filamentary, or from an impurity phase. Because the transport pressure cell uses a c-BN/epoxy medium (non-hydrostatic), filamentary conducting paths or contact artifacts could produce similar partial drops. If the transition is not bulk, the 'concurrent amorphization and superconductivity' narrative collapses, as does the claimed correlation between structural disorder and Tc. This is the weakest link because the amorphization evidence (XRD broad hump plus Raman mode reconstruction) is corroborated by two independent probes, whereas the SC evidence relies on a single transport signature with no thermodynamic or magnetic confirmation.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript reports a combined high-pressure transport, synchrotron X-ray diffraction, Raman spectroscopy, and DFT study of the topological material NbNiTe5. The authors identify a low-pressure structural anomaly near 4.5 GPa, followed by the onset of amorphization around 10 GPa. Concurrently, a resistance drop appears at ~0.6 K and rises to ~1.4 K by 45.7 GPa, and the drop is suppressed by an external magnetic field. These observations are interpreted as pressure-induced superconductivity emerging together with amorphization, with the degree of structural disorder modulating the superconducting transition temperature. The paper also discusses the possible role of disorder-driven reconstruction of the low-energy vibrational spectrum.","tokens_in":7866,"tokens_out":4819,"duration_ms":44529,"significance":"If the superconductivity is bulk, NbNiTe5 would be a rare case in which pressure-induced amorphization and superconductivity begin at the same pressure, with a tunable disorder–Tc relationship in a transition-metal chalcogenide. The structural evidence is solid: XRD shows a progressive loss of long-range order (broad hump after 20 GPa) and Raman spectra show reproducible mode reconstruction and low-frequency spectral-weight transfer. The transport data are consistent with superconductivity, but the key weakness is that the superconducting state is established only by a partial resistance drop with a 90%-onset criterion and no thermodynamic or magnetic confirmation. Given that the central narrative rests on this evidence, the claim is not yet fully established.","major_comments":[{"comment":"The superconducting claim rests solely on a partial resistance drop, with Tc defined at 90% of the normal-state resistance; no zero-resistance plateau, magnetic susceptibility, or specific-heat anomaly is reported. The field suppression at 31.0 and 45.7 GPa is consistent with superconductivity, but under the non-hydrostatic c-BN/epoxy pressure medium, filamentary or impurity superconducting paths (e.g., Te, Nb, Ni compounds) could produce similar partial drops. This is load-bearing for the 'concurrent amorphization and superconductivity' narrative. Please provide zero-resistance data to the base temperature, a shielding/susceptibility measurement, or a specific-heat anomaly; alternatively, a systematic study ruling out filamentary/impurity origin (e.g., multiple contact configurations, current dependence, several samples, post-run EDX/structural check).","section":"Results and Discussions, Fig. 2d–f, Tc definition"},{"comment":"The claim that superconductivity is 'modulated by the degree of disorder' is inferred from the temporal correlation between amorphization and the Tc increase. Pressure alone can enhance Tc, and the data do not separate the two variables. The Tc change is small (0.6–1.4 K), and the structural-disorder parameter evolves gradually over a wide pressure range. To support the disorder-modulation claim, the authors should plot a quantitative measure of disorder (e.g., XRD hump intensity or low-frequency Raman weight) against Tc and discuss whether the observed pressure dependence of Tc is consistent with known disorder-driven mechanisms rather than with generic pressure effects (e.g., increased electron–phonon coupling).","section":"Results and Discussions, 'Concurrent amorphization...' paragraph and Fig. 4"},{"comment":"The upper critical field Hc2(T) is extracted using the 90%-onset criterion. Onset-based Hc2 can substantially overestimate the bulk upper critical field, particularly in disordered or filamentary systems. The GL formula is also not typeset correctly in the text. Please provide the explicit equation and define the criterion used for each Hc2 data point; if possible, compare with the 50%-drop or zero-resistance criterion.","section":"Results and Discussions, Fig. 2f and generalized GL fit"}],"minor_comments":[{"comment":"The Birch–Murnaghan equation and the generalized GL formula are garbled in the text (special characters/braces misplaced). Please typeset them properly.","section":"Methods and Results, equations (BM and GL)"},{"comment":"Please label each curve in Fig. 2d with its pressure value. The text refers to data at 9.5, 31.0, and 45.7 GPa, but the figure should be self-explanatory.","section":"Figure 2d–f"},{"comment":"There are minor typos and spacing issues, e.g., 'N bNiTe5' in the abstract and 'TMC or halogenides' (should be 'halides') in the Introduction.","section":"Abstract and Introduction"},{"comment":"The term 'second-order transition' at ~4.5 GPa is inferred from lattice parameter anomalies and bulk-modulus change. This is suggestive, but a second-order transition normally requires thermodynamic evidence (e.g., specific heat). Please soften the terminology or add supporting evidence.","section":"Results and Discussions, second-order transition (Fig. 3b–c)"},{"comment":"The c-BN/epoxy medium in transport experiments is non-hydrostatic. Please acknowledge that this can affect the apparent amorphization pressure and contribute to broadening of the superconducting transition.","section":"Methods, pressure transmitting medium"}],"recommendation":"major_revision","confidential_remarks":"The paper fits the journal scope and the structural characterization is thorough, but the core claim of bulk superconductivity concurrent with amorphization currently rests on a partial resistance drop. I believe this can be fixed with additional measurements (susceptibility, specific heat, or zero resistance) or a detailed analysis excluding filamentary/impurity origins. The disorder-modulation interpretation is also presented more strongly than the correlational data justify; a quantitative disorder metric would materially strengthen the paper."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The genuinely new thing here is the material: NbNiTe5, a quasi-1D topological chalcogenide, turns amorphous above ~10 GPa and simultaneously develops a low-temperature resistance drop that sharpens and moves up to 1.4 K by 45.7 GPa. That puts it in a small club with In2Te5, the GST phase-change compounds, and (Ta/NbSe4)xI, and the paper makes that comparison honestly. The structural story is the strongest part: XRD shows a diffuse hump replacing the Bragg peaks, Raman shows mode reconstruction and a clear redistribution of spectral weight toward low frequencies, and the main features are reproduced in a second run. The low-pressure second-order transition near 4.5 GPa is corroborated by three independent probes (transport, cell parameters, bulk modulus), which gives me confidence in their high-pressure methodology overall.\n\nThe weak point is the superconductivity evidence, and it is exactly where the stress-test points. All we get is a partial resistance drop, defined at 90% of the normal-state value. There is no zero-resistance state, no susceptibility, no specific heat. Magnetic-field suppression makes a superconducting origin plausible, but it does not rule out filamentary or surface superconductivity, and the c-BN/epoxy pressure medium in the transport cell is explicitly non-hydrostatic, which could introduce current-path instabilities. Also, the claim that Tc tracks disorder is a correlation between two monotonic pressure trends; without a quantitative disorder metric, the connection remains suggestive rather than established. The paper itself says the link to the theoretical scenarios is 'qualitatively consistent' and needs future calculations, which is the right level of claim.\n\nI don't think these concerns are fatal. The pressure dependence of the transition and its field suppression are coherent, and amorphization is confirmed independently by XRD and Raman. But if I were the editor, I would not let this through without a referee asking for at least one thermodynamic or magnetic signature—either a small diamagnetic signal or a zero-resistance plateau—and a clear statement of the onset criterion. The paper deserves peer review because the observation, if confirmed, is a useful addition to a small but important family. I'd read it again after revision.\n\nWho should read it: anyone working on disorder-enhanced superconductivity or pressure-driven amorphization. I would probably not cite it yet in my own work until the bulk nature of the superconductivity is nailed down, but I'd bring it to a reading group.","headline":"A new data point in the short list of materials that superconduct under the same pressure that amorphizes them, with the superconducting evidence still thinner than the structural evidence.","tokens_in":8376,"tokens_out":3087,"would_cite":false,"duration_ms":26970,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"NbNiTe5 becomes amorphous and superconducting under the same compression, with the superconducting transition temperature rising as structural disorder increases.","keywords":["NbNiTe5","pressure-induced amorphization","superconductivity","structural disorder","topological material","transition metal chalcogenide","high-pressure transport","Raman spectroscopy"],"falsifier":"Measure AC susceptibility or heat capacity of NbNiTe5 in a diamond-anvil cell at about 45 GPa down to 0.3 K: a diamagnetic shielding signal or a specific-heat jump at the same 1.4 K where the resistance drops would confirm bulk superconductivity; the absence of either would indicate the resistance drop is not a bulk superconducting transition.","tokens_in":7470,"feed_emoji":"⚡","tokens_out":7029,"duration_ms":54111,"temperature":0.7,"pith_summary":"This paper reports that compressing the topological material NbNiTe5 past about 10 GPa triggers two changes at once: the crystal begins to lose long-range order and become amorphous, and it starts to show signs of superconductivity. As pressure rises to 45.7 GPa, the onset superconducting temperature climbs from 0.6 K to 1.4 K, so the more disordered the structure becomes, the higher Tc goes. The authors interpret this as disorder-driven superconductivity: amorphization preserves short-range chain motifs while redistributing low-energy vibrational modes, which plausibly strengthens the electron pairing. The finding matters because simultaneous pressure-induced amorphization and superconductivity is rarely seen, and it offers a controlled setting to test how structural disorder can enhance rather than destroy superconductivity. The evidence for superconductivity is a partial resistance drop that is suppressed by magnetic field, with no zero-resistance or thermodynamic signature reported.","feed_headline":"Amorphization and superconductivity arrive together at 10 GPa","feed_subtitle":"Higher pressure makes NbNiTe5 more disordered and raises its superconducting temperature from 0.6 K to 1.4 K.","key_machinery":"The load-bearing object is the quasi-1D crystal structure of NbNiTe5, built from Nb-Te distorted square antiprisms and Ni chains. Under pressure, this framework undergoes a gradual amorphization in which long-range periodicity is lost while short-range motifs survive. The key observable carrying the argument is the redistribution of Raman spectral weight toward low frequencies as disorder increases, which the paper links to softened and damped vibrations and, through recent theoretical proposals, to a stronger electron-phonon coupling that raises Tc.","core_discovery":"The central claim is that pressure-induced amorphization and superconductivity in NbNiTe5 begin at the same pressure, around 10 GPa, and that the superconducting transition temperature then rises monotonically with increasing structural disorder, from 0.6 K at 9.5 GPa to 1.4 K at 45.7 GPa. The paper supports this with three converging observations: X-ray diffraction shows a broad hump replacing crystalline peaks after 10 GPa, Raman spectra retain localized modes but develop new peaks and an enhanced low-frequency response, and four-probe resistance shows a magnetic-field-suppressed drop at low temperature. The authors propose that the gradual amorphization, which preserves short-range Nb-Te","pith_inferences":["If bulk thermodynamic probes later confirm the transition, the case becomes a direct example of disorder-controlled superconductivity in a topological semimetal; the transport-only evidence leaves filamentary or surface superconductivity as a live alternative explanation.","A quantitative prediction follows from the paper's interpretation: Tc should track the integrated low-frequency Raman spectral weight as pressure varies, so simultaneous transport and Raman measurements at low temperature could test the proposed mechanism.","The same gradual-amorphization window might be found by quick high-pressure resistance and diffraction screening of other chain-structure tellurides, expanding the known family of disorder-enhanced superconductors.","The paper's emphasis on preserved short-range motifs suggests a design heuristic: materials whose chain frameworks can lose long-range order without destroying local coordination are the most likely candidates for concurrent amorphization and superconductivity."],"forward_implications":["NbNiTe5 becomes a controlled laboratory for tuning the degree of structural disorder continuously between roughly 10 and 20 GPa while watching the superconducting onset in the same run.","The rise of Tc from 0.6 K at 9.5 GPa to 1.4 K at 45.7 GPa demonstrates that, in this material, increasing disorder accompanies rather than suppresses superconductivity.","The low-frequency Raman enhancement gives an experimentally accessible quantity that can be matched against models of phonon softening and electron-phonon coupling in disordered systems.","The paper predicts that comparable quasi-1D tellurides such as TaNiTe5 and TaPdTe5 are promising candidates for the same concurrent amorphization and superconductivity.","The upper critical field values (0.62 T at 31 GPa and 0.76 T at 45.7 GPa) provide a first estimate of pairing strength for future tests."],"fun_headline_variants":["Amorphization sparks superconductivity in pressurized NbNiTe5","Same pressure turns NbNiTe5 amorphous and superconducting","Disorder drives superconductivity in amorphized NbNiTe5","Pressure couples amorphization to superconductivity in NbNiTe5"],"cache_read_input_tokens":2304,"weakest_assumption_plain":"The load-bearing premise is that the low-temperature resistance drop—defined by the 90% onset criterion and suppressed by a magnetic field—genuinely marks bulk superconductivity in NbNiTe5, since no zero-resistance state, susceptibility, or specific-heat anomaly is reported.","fun_headline_variants_meta":{"raw":{"variants":["Amorphization sparks superconductivity in pressurized NbNiTe5","Same pressure turns NbNiTe5 amorphous and superconducting","Disorder drives superconductivity in amorphized NbNiTe5","Pressure couples amorphization to superconductivity in NbNiTe5"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.001682,"raw_usage":{"total_tokens":6489,"prompt_tokens":714,"completion_tokens":5775,"prompt_tokens_details":{"cached_tokens":256},"prompt_cache_hit_tokens":256,"prompt_cache_miss_tokens":458,"completion_tokens_details":{"reasoning_tokens":5704}},"tokens_in":458,"tokens_out":5775,"duration_ms":35712,"temperature":1.0,"reasoning_tokens":5704,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-04T08:59:25.884219+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure AC susceptibility or heat capacity of NbNiTe5 in a diamond-anvil cell at about 45 GPa down to 0.3 K: a diamagnetic shielding signal or a specific-heat jump at the same 1.4 K where the resistance drops would confirm bulk superconductivity; the absence of either would indicate the resistance drop is not a bulk superconducting transition.","supporting_citations":[],"review_version":1}